Signors to ahesicaw optical compawy



Patented duly 1Q, 1923.

U if T EDGAR D. TILLYEB AND JOHN F. XVIXTEID, OF

SIGNOBS 'IO AMERICAN OPTICAL COMPANY,

SOUTHBRIDGE, MASSACHUSETTS, AS OF SOUTHBPJIDGE, MASSACHUSETTS, A

VOLUNTARY ASSOCIATION OF MASSACHUSETTS.

LENS-MARKING DEVICE.

No Drawing.

To all whom it may concern:

Be it known that we, EDGAR D. TILLYER and JOHN VVIXTED, citizens of the United States, residing at Southbridge, in the county of lVorcester and State of Massachus-etts, have invented certain new and useful Improvements in Lens-Marking Devices, of which the following is a specification.

This invention relates to new and useful improvements in ophthalmic lenses and has particular reference to a novel and improved commercial article of the above type and to the art or process of producing this article.

Ophthalmic lenses at the present time are produced in various grades and types depending on the manufacturer producing the same, the accuracy and processes of manufacture of the particular type of lens involved. A new and improved process has been recently disclosed whereby the various types and characters of lenses may be readily marked so as to designate the particular type of lens and the manufacture without in any way destroying the surface of the lens, such marking being rendered visible only thru moisture applied thereto such as by the breath and is normally invisible, but not in any way impairing the vision thru the lens.

One of the main objects of our invention is the provision of a method whereby the designations as applied to the lens may be caused to remain visible after having been brought out in outline by the application of moisture to the surface of the lens such as breathing on the lens and remain visible until it is desired to eliminate the designation or render the same invisible.

A further object of our invention is the application of an oily substance to the surface of the lens which has been previously marked with the new and improved invisible markin whereby the marking is rendered visible and remains visible until the oily substance is removed from the surface of the lens, it being understood, however, that the usual manner in which the marking is rendered visible being first applied and then using the oily substance.

With the above and other objects in view the invention consists in the novel features of construction and other objects and advantages of the present invention will be readily apparent by reference to the following Application filed August 11, 1922. Serial No. 581,243.

specification. It will he understood that we may make any modification in the structure or step hereinafter described within the scope of the appended claims without de parting from or exceeding the spirit of our invention.

In carrying out our invention we first con struct a lens from ordinary crown or flint glass or a suitable combination of both, surfacing the lens in the usual manner on either one or both faces as may be preferred. After the lens has been finally finished on at least one surface it is in con dition for the carrying out of our process which consists in applying to the finished surface of the lens, either by pin, brush or other desired matter suitable designations, such as the trade mark, name of the manufacturer or the like.

The above application may he made with several different substances but as an example of one which we have found quite satisfactory is phosphoric acid. After the phosphoric acid has been applied to the polished surface of the lens. it is allowed to dry and any remaining substance removed .rom the surface of the lens and then by applying moisture such as by the breath, the designation which has been previously applied to the polished surface will be rendered visible although this designation is clearly invisible when the polished surface is in adry condition and this designation while invisible does not in any way interfere with the quality of the lens.

It is sometimes desirable to have the designation remain visible for a considerable length of time and in order to keep the visibility of the designation we apply to the polished surface of the lens an oily substance directly after the moisture has been applied thereto for rendering the designation visi-- ble. A careful study of this procedure will set forth the fact that the condition of the moisture upon the designation is different from that of the surrounding polished surface, the molecules of the moisture on the designation being considerably smaller than those of the surrounding surface, they will dry out much quicker and by applying the oily substance to the polished surface, the

oily substance will adhere to the dry surface but not adhere to the moisture on the surrounding surface. It is to be understood that in applying this oily substance it is preferred to apply the same quickly and lightly so that the substance will readily adhere to the dry surface of the designation and thus render the designation visible until the oily substance has been removed therefrom after which the designation will again be invisible.

We claim:

1. An ophthalmic lens having normally invisible markings thereon rendered visible when moistened and means to retain said markings in a visible state.

2. The art of marking ophthalmic lenses consisting in modifying portions of the optical surface to vary their action on condensed moisture applying moisture to said surface, subsequently applying a marking substance while the surface is in a moistened condition whereby the modified parts are retained in a state of different appearance for a predetermined length of time.

3. The art of invisibly marking glass surfaces, consisting in modifying the hydroscopic properties of portions of the surface of the lens, applying moisture thereto, and additionally applying an oily substance to the moistened surface to maintain said markings in a visible state.

a. The art of invisibly marking glass surfaces, consisting in applying to said surface a substance which will vary the hydroscopic properties of said surface applying moisture thereto and additionally applying an oily substance to the moistened surface to maintain said markings in a visible state.

EDGAR D. TILLYER. JOHN F. WIXTED. 

